diff --git a/fs/namei.c b/fs/namei.c index 5362af9b73729905817a76b5c24a5b33c48d5ce7..4ff7ca530533b121763dbe3b415ad79b162a85fb 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1748,6 +1748,9 @@ struct file *do_filp_open(int dfd, const char *pathname, if (!(open_flag & O_CREAT)) mode = 0; + /* Must never be set by userspace */ + open_flag &= ~FMODE_NONOTIFY; + /* * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only * check for O_DSYNC if the need any syncing at all we enforce it's diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index b04f88eed09e98b6134f275cb7ba530a06e7f998..f35794b97e8e5cb5cc396af28206d69ca1202935 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -92,7 +92,11 @@ static int fanotify_get_response_from_access(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p\n", __func__, group, event); - wait_event(group->fanotify_data.access_waitq, event->response); + wait_event(group->fanotify_data.access_waitq, event->response || + atomic_read(&group->fanotify_data.bypass_perm)); + + if (!event->response) /* bypass_perm set */ + return 0; /* userspace responded, convert to something usable */ spin_lock(&event->lock); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 063224812b7e607879bffeedd5b90f9c4967346f..8b61220cffc597873bc0292bbf2fcd86300f3d5c 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -106,20 +106,29 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event) return client_fd; } -static ssize_t fill_event_metadata(struct fsnotify_group *group, +static int fill_event_metadata(struct fsnotify_group *group, struct fanotify_event_metadata *metadata, struct fsnotify_event *event) { + int ret = 0; + pr_debug("%s: group=%p metadata=%p event=%p\n", __func__, group, metadata, event); metadata->event_len = FAN_EVENT_METADATA_LEN; + metadata->metadata_len = FAN_EVENT_METADATA_LEN; metadata->vers = FANOTIFY_METADATA_VERSION; metadata->mask = event->mask & FAN_ALL_OUTGOING_EVENTS; metadata->pid = pid_vnr(event->tgid); - metadata->fd = create_fd(group, event); + if (unlikely(event->mask & FAN_Q_OVERFLOW)) + metadata->fd = FAN_NOFD; + else { + metadata->fd = create_fd(group, event); + if (metadata->fd < 0) + ret = metadata->fd; + } - return metadata->fd; + return ret; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS @@ -200,7 +209,7 @@ static int prepare_for_access_response(struct fsnotify_group *group, mutex_lock(&group->fanotify_data.access_mutex); - if (group->fanotify_data.bypass_perm) { + if (atomic_read(&group->fanotify_data.bypass_perm)) { mutex_unlock(&group->fanotify_data.access_mutex); kmem_cache_free(fanotify_response_event_cache, re); event->response = FAN_ALLOW; @@ -257,24 +266,34 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p\n", __func__, group, event); - fd = fill_event_metadata(group, &fanotify_event_metadata, event); - if (fd < 0) - return fd; + ret = fill_event_metadata(group, &fanotify_event_metadata, event); + if (ret < 0) + goto out; + fd = fanotify_event_metadata.fd; ret = prepare_for_access_response(group, event, fd); if (ret) goto out_close_fd; ret = -EFAULT; - if (copy_to_user(buf, &fanotify_event_metadata, FAN_EVENT_METADATA_LEN)) + if (copy_to_user(buf, &fanotify_event_metadata, + fanotify_event_metadata.event_len)) goto out_kill_access_response; - return FAN_EVENT_METADATA_LEN; + return fanotify_event_metadata.event_len; out_kill_access_response: remove_access_response(group, event, fd); out_close_fd: - sys_close(fd); + if (fd != FAN_NOFD) + sys_close(fd); +out: +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (event->mask & FAN_ALL_PERM_EVENTS) { + event->response = FAN_DENY; + wake_up(&group->fanotify_data.access_waitq); + } +#endif return ret; } @@ -382,7 +401,7 @@ static int fanotify_release(struct inode *ignored, struct file *file) mutex_lock(&group->fanotify_data.access_mutex); - group->fanotify_data.bypass_perm = true; + atomic_inc(&group->fanotify_data.bypass_perm); list_for_each_entry_safe(re, lre, &group->fanotify_data.access_list, list) { pr_debug("%s: found group=%p re=%p event=%p\n", __func__, group, @@ -586,11 +605,10 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, { struct fsnotify_mark *fsn_mark; __u32 added; + int ret = 0; fsn_mark = fsnotify_find_vfsmount_mark(group, mnt); if (!fsn_mark) { - int ret; - if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks) return -ENOSPC; @@ -600,17 +618,16 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, fsnotify_init_mark(fsn_mark, fanotify_free_mark); ret = fsnotify_add_mark(fsn_mark, group, NULL, mnt, 0); - if (ret) { - fanotify_free_mark(fsn_mark); - return ret; - } + if (ret) + goto err; } added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); - fsnotify_put_mark(fsn_mark); + if (added & ~mnt->mnt_fsnotify_mask) fsnotify_recalc_vfsmount_mask(mnt); - - return 0; +err: + fsnotify_put_mark(fsn_mark); + return ret; } static int fanotify_add_inode_mark(struct fsnotify_group *group, @@ -619,6 +636,7 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group, { struct fsnotify_mark *fsn_mark; __u32 added; + int ret = 0; pr_debug("%s: group=%p inode=%p\n", __func__, group, inode); @@ -634,8 +652,6 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group, fsn_mark = fsnotify_find_inode_mark(group, inode); if (!fsn_mark) { - int ret; - if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks) return -ENOSPC; @@ -645,16 +661,16 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group, fsnotify_init_mark(fsn_mark, fanotify_free_mark); ret = fsnotify_add_mark(fsn_mark, group, inode, NULL, 0); - if (ret) { - fanotify_free_mark(fsn_mark); - return ret; - } + if (ret) + goto err; } added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); - fsnotify_put_mark(fsn_mark); + if (added & ~inode->i_fsnotify_mask) fsnotify_recalc_inode_mask(inode); - return 0; +err: + fsnotify_put_mark(fsn_mark); + return ret; } /* fanotify syscalls */ @@ -687,8 +703,10 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) /* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */ group = fsnotify_alloc_group(&fanotify_fsnotify_ops); - if (IS_ERR(group)) + if (IS_ERR(group)) { + free_uid(user); return PTR_ERR(group); + } group->fanotify_data.user = user; atomic_inc(&user->fanotify_listeners); @@ -698,6 +716,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) mutex_init(&group->fanotify_data.access_mutex); init_waitqueue_head(&group->fanotify_data.access_waitq); INIT_LIST_HEAD(&group->fanotify_data.access_list); + atomic_set(&group->fanotify_data.bypass_perm, 0); #endif switch (flags & FAN_ALL_CLASS_BITS) { case FAN_CLASS_NOTIF: @@ -764,8 +783,10 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags, if (flags & ~FAN_ALL_MARK_FLAGS) return -EINVAL; switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) { - case FAN_MARK_ADD: + case FAN_MARK_ADD: /* fallthrough */ case FAN_MARK_REMOVE: + if (!mask) + return -EINVAL; case FAN_MARK_FLUSH: break; default: diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 444c305a468c531b7e9e8dda803a2d650a257c58..4cd5d5d78f9fa2b85f38bd9422efc3d387780295 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -752,6 +752,7 @@ SYSCALL_DEFINE1(inotify_init1, int, flags) if (ret >= 0) return ret; + fsnotify_put_group(group); atomic_dec(&user->inotify_devs); out_free_uid: free_uid(user); diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index 0f0121467fc4b8cf261cbb06a9ff6347b3596474..6c6133f76e163c88041c4a13a4b091ef6ccf13ac 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -83,11 +83,13 @@ FAN_ALL_PERM_EVENTS |\ FAN_Q_OVERFLOW) -#define FANOTIFY_METADATA_VERSION 2 +#define FANOTIFY_METADATA_VERSION 3 struct fanotify_event_metadata { __u32 event_len; - __u32 vers; + __u8 vers; + __u8 reserved; + __u16 metadata_len; __aligned_u64 mask; __s32 fd; __s32 pid; @@ -96,11 +98,13 @@ struct fanotify_event_metadata { struct fanotify_response { __s32 fd; __u32 response; -} __attribute__ ((packed)); +}; /* Legit userspace responses to a _PERM event */ #define FAN_ALLOW 0x01 #define FAN_DENY 0x02 +/* No fd set in event */ +#define FAN_NOFD -1 /* Helper functions to deal with fanotify_event_metadata buffers */ #define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata)) diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 5c185fa27089f03b4e9194445ee7bfd842f125c6..b10bcdeaef768b2b0b123c4a6c862b3f5f6c0694 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -235,9 +235,6 @@ static inline void fsnotify_open(struct file *file) if (S_ISDIR(inode->i_mode)) mask |= FS_ISDIR; - /* FMODE_NONOTIFY must never be set from user */ - file->f_mode &= ~FMODE_NONOTIFY; - fsnotify_parent(path, NULL, mask); fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 0a68f924f06fcf3f6f75727f382971bc16e5608f..7380763595d30accb255728f45682550cc540d63 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -166,7 +166,7 @@ struct fsnotify_group { struct mutex access_mutex; struct list_head access_list; wait_queue_head_t access_waitq; - bool bypass_perm; /* protected by access_mutex */ + atomic_t bypass_perm; #endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */ int f_flags; unsigned int max_marks;